Optical components are extensively used in data communication networks. Typically these components are designed to propagate optical signals. In order to preserve signal integrity it is important to maintain certain optical characteristics. One of these characteristics is polarization dependent loss. Polarization dependant loss causes differing optical signals having substantially equal wavelengths to experience different attenuation characteristics in optical components. Since attenuation is critical for a variety of reasons it is necessary to ensure that the intensity of an optical signal is predictable in order to ensure the signal to noise ratio is within an acceptable range.
This is a key concern for optical network designers because different lasers have different polarization characteristics. Additionally, it is known that many different types of integrated optical components suffer very high polarization dependant loss. As more of these components are introduced into an optical network problems arising from polarization dependant loss are complicated.
Clearly, it would be beneficial to have integrated optical components which are polarization insensitive.